Several communication technologies have been previously used to provide high data race wired communication with each having various associated advantages and disadvantages.
One technology, DSL (Digital Subscriber Loop) encompasses various !3tandards such as ADSL (Asymmetric DSL) and VDSL (Very high titrate DSL) in which a single pair of wires is used from the cable plant for each communication channel. Methods exist for combining a small number of pairs for subscriber premises; however, for each subscriber serviced, a dedicated pair is used.
Another technology, SHDSL (Symmetrical High-speed DSL), and technologies similar to it, employ multiple pairs of wires for each subscriber in order to increase the bandwidth available per subscriber. Each pair taken from the cable to a given subscriber is not available to subsequent subscribers further downstream on the distribution cable.
Hybrid Fiber Coax (HFC), another technology uses a shared coax cable for data communication between a plant and multiple subscribers. Consequently, each subscriber has access to a large amount of shared bandwidth. The shared coax cable is expensive and is not available to many subscribers who live in areas where it has not been economical to install. Shared coax cable systems are generally owned by a single communications company in a particular area, while a competing provider might not have a coax cable infrastructure. Additionally, with a shared coax infrastructure, upstream traffic from individual subscribers is present at each subscriber interface, resulting in a potential security issue. By contrast, a twisted pair infrastructure is available to almost every home and business in developed parts of the world.